org.eel.kitchen.jsonschema.ref

Class JsonRef

java.lang.Object

org.eel.kitchen.jsonschema.ref.JsonRef

public final class JsonRef
extends Object

Representation of a JSON Reference

JSON Reference, currently a draft, is a way to define a path within a JSON document.

To quote the draft, "A JSON Reference is a JSON object, which contains a member named "$ref", which has a JSON string value." This string value must be a URI. Example:

     {
         "$ref": "http://example.com/example.json#/foo/bar"
     }
 

This class is used in a more general way than the draft. It is also used as a backing class for schema identifiers.

The implementation is a wrapper over Java's URI, with the following differences:

• all URIs are normalized from the get go;
• an empty fragment is equivalent to no fragment at all, and stands for a root JSON Pointer;
• a reference is taken to be absolute if the underlying URI is absolute and it has no fragment, or an empty fragment.

This class is thread safe and immutable.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	contains(JsonRef other) Tell whether the current JSON Reference contains another
static JsonRef	emptyRef() Return an empty reference
boolean	equals(Object obj)
static JsonRef	fromNode(JsonNode node) Build a JSON Reference from a JsonNode
static JsonRef	fromString(String s) Build a JSON Reference from a string input
static JsonRef	fromURI(URI uri) Build a JSON Reference from a URI
JsonFragment	getFragment() Return this JSON Reference's fragment
URI	getRootAsURI() Return this JSON Reference's locator
int	hashCode()
boolean	isAbsolute() Tell whether this reference is an absolute reference
JsonRef	resolve(JsonRef other) Resolve this reference against another reference
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

fromURI

public static JsonRef fromURI(URI uri)

Build a JSON Reference from a URI

Parameters:

uri - the provided URI

Returns:

the JSON Reference

Throws:

NullPointerException - the provided URI is null

See Also:

JsonRef(URI)

fromString

public static JsonRef fromString(String s)
                          throws JsonSchemaException

Build a JSON Reference from a string input

Parameters:

s - the string

Returns:

the reference

Throws:

JsonSchemaException - string is not a valid URI

NullPointerException - provided string is null

fromNode

public static JsonRef fromNode(JsonNode node)
                        throws JsonSchemaException

Build a JSON Reference from a JsonNode

If the node is not textual, this returns an empty reference. Otherwise, it calls fromString(String) with this node's text value.

Parameters:

node - the node

Returns:

the reference

Throws:

JsonSchemaException - see fromString(String)

NullPointerException - provided node is null

emptyRef

public static JsonRef emptyRef()

Return an empty reference

An empty reference is a reference which only has an empty fragment.

Returns:

see above

isAbsolute

public boolean isAbsolute()

Tell whether this reference is an absolute reference

A JSON Reference is considered absolute iif the underlying URI is itself absolute and it has an empty, or no, fragment part.

Returns:

see above

resolve

public JsonRef resolve(JsonRef other)

Resolve this reference against another reference

Note: jar URIs need to be special cased, see resolveJarURI(JsonRef).

Parameters:

other - the reference to resolve

Returns:

the resolved reference

getRootAsURI

public URI getRootAsURI()

Return this JSON Reference's locator

The locator of a fragment is the URI with an empty fragment.

Returns:

an URI

getFragment

public JsonFragment getFragment()

Return this JSON Reference's fragment

Returns:

the fragment

contains

public boolean contains(JsonRef other)

Tell whether the current JSON Reference contains another

This is considered true iif both references have the same locator, in other words, if they differ only by their fragment part.

Parameters:

other - the other reference

Returns:

see above

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object